running CiviCRM 4.7.8 WordPress
The following is appearing in the error_log whenever cron.php runs:
[Fri Jun 24 16:01:06 2016] [error] [client ...] PHP Warning: date(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected the timezone 'UTC' for now, but please set date.timezone to select your timezone. in /.../wp-content/plugins/civicrm/civicrm/CRM/Mailing/Event/BAO/Opened.php on line 58
Is anyone aware which class is supposed to be responsible for setting the timezone in this case?